1. Field of the Invention
The present invention relates to a pattern specification method and a pattern specification apparatus which specify a drawn microscopic pattern.
2. Description of the Related Art
In recent years, the dimension of a microscopic pattern drawn on a semiconductor LSI or a mask (reticle) has been measured so as to enhance a quality, an available percentage, etc.
Heretofore, a person has designated and precisely measured a pattern to-be-measured by reference to design data in such a way that the drawn pattern is scanned with an electron beam finely focused in a scanning electron microscope (hereinbelow, abbreviated to “SEM”), that emitted secondary electrons are detected so as to synchronously display a SEM image on a screen, and that the enlarged pattern of the pattern to-be-measured is displayed on the SEM image.
Therefore, in a case where the integration density of semiconductor LSI patterns heightens, where the dimensions and precision of the designed patterns are made as fine as 0.036 μm and ±0.005 μm or so, respectively, and where the number of similar patterns becomes very large, it has become difficult to the person to have the design data displayed on the screen, and to satisfactorily confirm and specify the pattern to-be-measured on the image so as to precisely perform a length measurement. Besides, it has occurred as another problem that the number of the patterns whose lengths are to be measured increases (to, for example, several hundreds to several thousands), so the person is, in effect, incapable of specifying the patterns one by one.
Especially when the dimension of the pattern becomes small as stated above, the width of the pattern fabricated by actual drawing becomes larger or smaller than the design data under the intenser influence of the processes of a resist (processes such as drawing, developing and etching). Unless the influence of the processes of the resist are considered, it is very difficult for a person to specify the pattern for the length measurement or the like, among a plurality of patterns whose widths are similar, but are slightly different. Accordingly, there has been the problem that mistakes often occur.